Process for preparing a methylene-bridged biscyclopentadienyl compound

Abstract

Process for preparing a methylene-bridged cyclopentadienyl compound The present invention relates to a process for preparing a methylene-bridged biscyclopentadienyl compound having the formula I ##STR1## Where L are, independently of one another, identical or different and are each a cyclopentadienyl group, by reactin one or two cyclopentadienyl compounds LH with formaldehyde in monomeric, oligomeric or polymeric form or formaldehyde-generating reagents in the presence of at least one base and at least one phase transfer catalyst.

We claim: 
     
       1. A process for preparing a methylene-bridged biscyclopentadienyl compound having the formula I ##STR5## where L are, independently of one another, identical or different and are each a cyclopentadienyl group, by reacting one or two cyclopentadienyl compounds LH with formaldehyde in monomeric, oligomeric or polymeric form or formaldehyde-generating reagents in the presence of at least one base and at least one phase transfer catalyst. 
     
     
       2. The process as claimed in claim 1, wherein the process is carried out in a multiphase system. 
     
     
       3. The process as claimed in claim 1, wherein the process is carried in a two-phase system which comprises an organic solvent and water. 
     
     
       4. The process as claimed in claim 1, wherein the base is a hydroxide of group Ia, IIa or IIIa of the Periodic Table of the Elements. 
     
     
       5. The process as claimed in claim 1, wherein the phase transfer catalyst is a quaternary ammonium salt, a quaternary phosphonium salt or a crown compound. 
     
     
       6. The process as claimed in claim 1, wherein, in formula I, one or both cyclopentadienyl groups L are substituted cyclopentadienyl groups. 
     
     
       7. A process for preparing a methylene-bridged cyclopentadienyl metallocene, comprising the steps a) preparing a methylene-bridged biscyclopentadienyl compound by the process as claimed in one or more of claims 1 to 6, and   b) reacting the carbon-bridged biscyclopentadienyl compound obtained in step a) with a metal compound M 1  X p , where M 1  is an element of group IIIb, IVb, Vb or VIb of the Periodic Table of the Elements, X is a C 1  -C 40  -radical, a halogen or a pseudohalogen and p is an integer from 0 to 4, under conditions under which the methylene-bridged biscyclopentadienyl compound obtained in step a) is complexed to give the methylene-bridged biscyclopentadienyl metallocene.   
     
     
       8. The process as claimed in claim 7, wherein M 1  is an element of group IVb. 
     
     
       9. The process as claimed in claim 7, wherein said methylene-bridge biscyclopentadienyl is of the formula V ##STR6## where M 1  is an element of group IIIb, IVb, Vb or VIb of the Periodic Table of the Elements, L' are, independently of one another, identical or different and are each a cyclopentadienyl group, and   R 11  and R 12  are identical or different and are each hydrogen, a halogen atom or a C 1  -C 40  -radical such as C 1  -C 10  -alkyl, C 1  -C 10  -alkoxy, C 6  -C 14  -aryl, C 6  -C 14  -aryloxy, C 2  -C 10  -alkenyl, C 7  -C 40  -arylalkyl, C 7  -C 40  -alkylaryl, C 8  -C 40  -arylalkenyl, hydroxy, NR 5   2 , where R 5  is C 1  -C 10  -alkyl, C 1  -C 10  -alkoxy, C 6  -C 14  -aryl, C 6  -C 14  -aryloxy, C 2  -C 10  -alkenyl, C 7  -C 40  -arylalkyl, C 7  -C 40  -alkylaryl or C 8  -C 40  -arylalkenyl.   
     
     
       10. The process as claimed in claim 9, wherein M 1  is an element of group IVb, of the Periodic Table of Elements, L' are identical or different and are unsubstituted cyclopentadienyl, tetramethylcyclopentadienyl, 3-methylcyclopentadienyl, 3-tert-butylcyclopentadienyl, methyl-tertbutylcyclopentadienyl, isopropylcyclopentadienyl, dimethylcyclopentadienyl, trimethylcyclopentadienyl, trimethylethylcyclopentadienyl, 3-phenylcyclopentadienyl, diphenylcyclopentadienyl, 3-trimethylsilylcyclopentadienyl, indenyl, 2-methylindenyl, 2-ethylindenyl, 3-methylindenyl, 3-tert-butylindenyl, 3-trimethylsilylindenyl, 2-methyl-4-phenylindenyl, 2-ethyl-4-phenylindenyl, 2-methyl-4-naphthylindenyl, 2-methyl-4-isopropylindenyl, benzoindenyl, 2-methyl -4,5-benzoindenyl, 2-methyl-α-acenaphthylindenyl, 2-methyl-4,6-diisopropylindenyl, fluorenyl, 2-methylfluorenyl, 2,7-diphenylfluorenyl or 2,7-di-tert-butylfluorenyl and R 11  and R 12  are identical or different and are C 1  -C 4  -alkyl or a halogen atom.   
     
     
       11. The process as claimed in claim 10, wherein said methylene-bridge biscyclopentadienyl metallocene is methylene-bis(cyclopentadienyl)zirconium dichloride,   methylene-bis(2,3,4,5-tetramethylcyclopentadienyl)zirconium dichloride,   methylene-bis(2,3,4-trimethylcyclopentadienyl)zirconium dichloride,   methylene-bis(1-indenyl)zirconium dichloride,   methylene-bis(1-(2-methylindenyl)zirconium dichloride,   methylene-bis(1-(4-phenylindenyl))zirconium dichloride,   methylene-bis(1-(4-isopropylindenyl))zirconium dichloride,   methylene-bis(1-(4-isopropylindenyl))hafnium dichloride,   methylene-bis(1-(4,5-benzoindenyl)zirconium dichioride,   methylene-bis(1-(4,5-benzoindenyl))hafnium dichloride,   methylene-(1-indenyl)cyclopentadienylzirconium dichloride,   methylene-(1-indenyl)(3-methylcyclopentadienyl)zirconium dichioride,   methylene-(1-(4-isopropyl)indenyl)cyclopentadienylzirconium dichloride,   methylene-(1-indenyl)cyclopentadienyltitanium dichioride,   methylene-(1-indenyl)(3-methylcyclopentadienyl)titanium dichloride,   methylene-(1-indenyl)(9-fluorenyl)zirconium dichloride,   methylene-(9-fluorenyl)(3-methylcyclopentadienyl)zirconium dichloride,   methylene-(9-luorenyl)(34ert-butylcyclopentadienyl)zirconium dichloride,   methylene-(9-fluorenyl)cyclo pentadienylzirconium dichloride,   methylene-(9-(2,7-di-tert-butyl)fluorenyl)cyclopentadienylzirconium dichloride or   methylene-(9-(2,7-diphenyl)fluorenyl)cyclopentadienylzirconium dichloride.